RETROFIT OF UNREINFORCED MASONRY CLADDING FOLLOWINGTHE 2001 NISQUALLY EARTHQUAKE

摘要

The 2001 Nisqually earthquake shook western Washington State and caused significant damage tounreinforced masonry (URM) structures in Seattle. Repairs to damaged URM buildings began shortlyafter the earthquake. Two buildings, the PacMed/Amazon and Starbucks Center suffered extensivedamage to their URM exterior cladding systems.The exterior cladding on the top three floors of the 16-story PacMed/Amazon building was removed brickby brick and reconstructed with a visually identical new cladding system called reinforced veneer. Theentire exterior cladding of the nine-story Starbucks Center building was removed and replaced. Part of thebuilding was replaced with conventional brick veneer over metal studs; the remainder was replaced withreinforced brick cladding panels.This paper will briefly discuss the seismological aspects of the Nisqually earthquake and how the regionwas affected by the event. Subsequently, both the PacMed/Amazon and the Starbucks Center buildingscladding retrofits will be discussed. The discussion will include background information, sustainedearthquake cladding damage, the cladding retrofit technique, and the cladding retrofit construction foreach building.